ASTM D7251-06e1

Standard Specification for Color and Appearance Retention of Variegated Color Plastic Siding Products

ABSTRACT
This specification establishes requirements and test methods for the color and appearance retention of variegated color plastic siding products. Color retention testing provides a method for estimating the acceptability of color change in a siding product over a period of years of service. Characterization of color and appearance for variegated colors is complicated by the presence of multiple colors in a random pattern. The procedure is based on using a template to reference 6 spots for color measurement. The color region for a color is determined by measuring the Hunter L, a, b color values for a sample population and calculating the average Hunter L, a, b color value. Ellipsoid Value Equations are used to determine the ellipsoid value representing the change in color due to weathering. Samples shall be exposed at three test sites: Temperate Northern represented by a site located in Louisville, KY or Cleveland, OH; hot, humid represented by a site located in Miami, FL, and hot, dry represented by a site located in Phoenix, Arizona. Materials shall be tested and the individual grades shall conform to specified values of ellipsoid value, color retention, and variegation change.
SCOPE
1.1 This specification establishes requirements and test methods for the color and appearance retention of variegated color plastic siding products.
1.2 Color retention testing provides a method for estimating the acceptability of color change in a siding product over a period of years of service.
1.3 Characterization of color and appearance for variegated colors is complicated by the presence of multiple colors in a random pattern. The procedure is based on using a template to reference 6 spots for color measurement.
1.4 Methods of indicating compliance with this specification are provided.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.Note 1
There is no known ISO equivalent to this standard.

General Information

• Status: Historical
• Publication Date: 31-Mar-2006
• ICS: 01.070 - Colour coding
• ICS: 83.080.01 - Plastics in general
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.24 - Plastic Building Products

Relations

• Replaces: ASTM D7251-06 - Standard Specification for Color and Appearance Retention of Variegated Color Plastic Siding Products
• Effective Date: 01-Apr-2006
• Replaced By: ASTM D7251-09 - Standard Specification for Color and Appearance Retention of Variegated Color Plastic Siding Products
• Effective Date: 01-Nov-2009
• Referred By: ASTM D7856-21 - Standard Specification for Color and Appearance Retention of Solid and Variegated Color Plastic Siding Products using CIELab Color Space
• Effective Date: 01-Apr-2006

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
An American National Standard
´1
Designation: D7251 – 06
Standard Specification for
Color and Appearance Retention of Variegated Color Plastic
1
Siding Products
This standard is issued under the fixed designation D7251; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1
´ NOTE—Fig. 1 was editorially revised in September 2006.
1. Scope G147 Practice for Conditioning and Handling of Nonmetal-
lic Materials for Natural and Artificial Weathering Tests
1.1 This specification establishes requirements and test
methods for the color and appearance retention of variegated
3. Terminology
color plastic siding products.
3.1 Definitions—Definitions are in accordance with termi-
1.2 Color retention testing provides a method for estimating
nologies in Terminologies D883 and D1600 unless otherwise
the acceptability of color change in a siding product over a
noted.
period of years of service.
3.2 Definitions of Terms Specific to This Standard:
1.3 Characterization of color and appearance for variegated
3.2.1 color region—parameters that define the color space
colors is complicated by the presence of multiple colors in a
for a siding measured with Hunter Units, Illuminant C, 2°
random pattern. The procedure is based on using a template to
Observer, specular component included.
reference 6 spots for color measurement.
3.2.1.1 Discussion—Thecolorvaluesusedtoclassifycolors
1.4 Methods of indicating compliance with this specifica-
by region will be established by measuring the Hunter L, a, b
tion are provided.
color values from the sample population, calculating the
1.5 This standard does not purport to address all of the
average for Hunter L, a, b, and then choosing the integer from
safety concerns, if any, associated with its use. It is the
the corresponding L, a, b average values (that is, no rounding
responsibility of the user of this standard to establish appro-
up or down) to be used to classify colors by region.
priate safety and health practices and determine the applica-
3.2.2 color retention standards—predictive color regions
bility of regulatory limitations prior to use.
described by a three dimensional model which constitute
NOTE 1—There is no known ISO equivalent to this standard.
acceptable color retention levels resulting from weathering of
a specific product type and color.
2. Referenced Documents
3.2.2.1 Discussion—Color retention standards are defined
2
2.1 ASTM Standards:
by equations that describe the three dimensional ellipsoid
D883 Terminology Relating to Plastics
value.
D1435 Practice for Outdoor Weathering of Plastics
3.2.3 ellipsoid value—a mathematical calculation derived
D1600 Terminology for Abbreviated Terms Relating to
by inserting the measured DL, Da, and Db values of a
Plastics
weathered specimen into an ellipsoid equation.
D2244 Practice for Calculation of Color Tolerances and
3.2.4 variegated plastic siding—siding having discrete
Color Differences from Instrumentally Measured Color
markings of different colors.
Coordinates
E805 Practice for Identification of Instrumental Methods of 4. Classification
Color or Color-Difference Measurement of Materials
4.1 Definitions—Definitions are in accordance with termi-
nology in Terminologies D883 and D1600 unless otherwise
noted.
1
This specification is under the jurisdiction of ASTM Committee D20 on
4.2 Color Regions—The color region for a color is deter-
Plastics and is the direct responsibility of Subcommittee D20.24 on Plastic Building
mined by measuring the Hunter L, a, b color values for a
Products.
sample population and calculating the average Hunter L, a, b
Current edition approved April 1, 2006. Published April 2006. DOI: 10.1520/
D7251-06E01.
color value. Use the integer value (by truncating any fractional
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
result)oftheaveragetodeterminethecolorregionforthecolor
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
using the following region boundaries.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. 4.2.1 Region 1—Brown
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D7251 – 06
4.2.16 Region 16—Dark Red
L = 20 to 49
a=–1to5
L = 25 to 49
b=2to11
a=6to30
b=–1to25
4.2.2 Region 2—Medium Blue
4.3 Ellipsoid Value Equations—Usethefollowingequations
L = 45 to 64
a=–8to1
to determine the ellipsoid value representing the change in
b = –12 to –2
color due to weathering. Use the equation that co
...